Health Topics

Diagnostic tests

Heart Health Tests
National Library of Medicine
Cardiac Test
Heart Test
Cardiac Diagnostic Tests

Heart diseases are the number one killer in the U.S. They are also a major cause of disability. If you do have a heart disease, it is important to find it early, when it is easier to treat. Blood tests and heart health tests can help find heart diseases or identify problems that can lead to heart diseases. There are several different types of heart health tests. Your doctor will decide which test or tests you need, based on your symptoms (if any), risk factors, and medical history.

Cardiac Catheterization

Cardiac catheterization is a medical procedure used to diagnose and treat some heart conditions. For the procedure, your doctor puts a catheter (a long, thin, flexible tube) into a blood vessel in your arm, groin, or neck, and threads it to your heart. The doctor can use the catheter to

  • Do a coronary angiography. This involves putting a special type of dye in the catheter, so the dye can flow through your bloodstream to your heart. Then your doctor takes x-rays of your heart. The dye allows your doctor to see your coronary arteries on the x-ray, and to check for coronary artery disease (plaque buildup in the arteries).
  • Take samples of blood and heart muscle
  • Do procedures such as minor heart surgery or angioplasty, if your doctor finds that you need it
Cardiac CT Scan

A cardiac CT (computed tomography) scan is a painless imaging test that uses x-rays to take detailed pictures of your heart and its blood vessels. Computers can combine these pictures to create a three-dimensional (3D) model of the whole heart. This test can help doctors detect or evaluate

  • Coronary artery disease
  • Calcium buildup in the coronary arteries
  • Problems with the aorta
  • Problems with heart function and valves
  • Pericardial diseases

Before you have the test, you get an injection of contrast dye. The dye highlights your heart and blood vessels in the pictures. The CT scanner is a large, tunnel-like machine. You lie still on a table which slides you into the scanner, and the scanner takes the pictures for about 15 minutes.

Cardiac MRI

Cardiac MRI (magnetic resonance imaging) is a painless imaging test that uses radio waves, magnets, and a computer to create detailed pictures of your heart. It can help your doctor figure out whether you have heart disease, and if so, how severe it is. A cardiac MRI can also help your doctor decide the best way to treat heart problems such as

  • Coronary artery disease
  • Heart valve problems
  • Pericarditis
  • Cardiac tumors
  • Damage from a heart attack

The MRI is a large, tunnel-like machine. You lie still on a table which slides you into the MRI machine. The machine makes loud noises as it takes pictures of your heart. It usually takes about 30-90 minutes. Sometimes before the test, you might get an injection of contrast dye. The dye highlights your heart and blood vessels in the pictures.

Chest X-Ray

A chest x-ray creates pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. It can reveal signs of heart failure, as well as lung disorders and other causes of symptoms not related to heart disease.

Coronary Angiography

Coronary angiography (angiogram) is a procedure that uses contrast dye and x-ray pictures to look at the insides of your arteries. It can show whether plaque is blocking your arteries and how severe the blockage is. Doctors use this procedure to diagnose heart diseases after chest pain, sudden cardiac arrest (SCA), or abnormal results from other heart tests such as an EKG or a stress test.

You usually have a cardiac catheterization to get the dye into your coronary arteries. Then you have special x-rays while the dye is flowing through your coronary arteries. The dye lets your doctor study the flow of blood through your heart and blood vessels.

Echocardiography

Echocardiography, or echo, is a painless test that uses sound waves to create moving pictures of your heart. The pictures show the size and shape of your heart. They also show how well your heart's chambers and valves are working. Doctors use an echo to diagnose many different heart problems, and to check how severe they are.

For the test, a technician applies gel to your chest. The gel helps sound waves reach your heart. The technician moves a transducer (wand-like device) around on your chest. The transducer connects to a computer. It transmits ultrasound waves into your chest, and the waves bounce (echo) back. The computer converts the echoes into pictures of your heart.

Electrocardiogram (EKG), (ECG)

An electrocardiogram, also called an ECG or EKG, is a painless test that detects and records your heart's electrical activity. It shows how fast your heart is beating and whether its rhythm is steady or irregular.

An EKG may be part of a routine exam to screen for heart disease. Or you may get it to detect and study heart problems such as heart attacks, arrhythmia, and heart failure.

For the test, you lie still on a table and a nurse or technician attaches electrodes (patches that have sensors) to the skin on your chest, arms, and legs. Wires connect the electrodes to a machine that records your heart's electrical activity.

Stress Testing

Stress testing looks at how your heart works during physical stress. It can help to diagnose coronary artery disease, and to check how severe it is. It can also check for other problems, including heart valve disease and heart failure.

For the test, you exercise (or are given medicine if you are unable to exercise) to make your heart work hard and beat fast. While this is happening, you get an EKG and blood pressure monitoring. Sometimes you may also have an echocardiogram, or other imaging tests such as a nuclear scan. For the nuclear scan, you get an injection of a tracer (a radioactive substance), which travels to your heart. Special cameras detect the energy from the tracer to make pictures of your heart. You have pictures taken after you exercise, and then after you rest.

NIH: National Heart, Lung, and Blood Institute


Diagnostic Techniques, Cardiovascular
Heart Function Tests
Blood, Heart and Circulation
Heart diseases are the number one killer in the U.S. They are also a major cause of disability. If you do have a heart disease, it is important to find it ...
COVID-19 Testing
National Library of Medicine
COVID-19 Antibody Test
COVID-19 Viral Test
SARS-CoV-2 Testing

COVID-19 (coronavirus disease 2019) is an illness caused by a virus. This virus is a new coronavirus that has spread throughout the world. It is called SARS-CoV-2. There are two types of tests for this virus:

  • A viral test tells you if you have a current infection
  • An antibody (serology) test might tell you if you had a past infection

If you think that you need a COVID-19 test, contact your health care provider. You can also check your state or local health department's website for information on testing in your area.

Even if a test shows that you do not currently have COVID-19, you should still take steps to protect yourself and others.

Centers for Disease Control and Prevention


COVID-19 Testing
Diagnostic Tests
COVID-19 (coronavirus disease 2019) is an illness caused by a virus. This virus is a new coronavirus that has spread throughout the world. It is called SARS- ...
Prenatal Testing
National Library of Medicine
Amniocentesis
Chorionic Villi Sampling
Fetal Ultrasound

Prenatal testing provides information about your baby's health before he or she is born. Some routine tests during pregnancy also check on your health. At your first prenatal visit, your health care provider will test for a number of things, including problems with your blood, signs of infections, and whether you are immune to rubella (German measles) and chickenpox.

Throughout your pregnancy, your health care provider may suggest a number of other tests, too. Some tests are suggested for all women, such as screenings for gestational diabetes, Down syndrome, and HIV. Other tests might be offered based on your

  • Age
  • Personal or family medical history
  • Ethnic background
  • Results of routine tests

There are two types of tests:

  • Screening tests are tests that are done to see if you or your baby might have certain problems. They evaluate risk, but do not diagnose problems. If your screening test result is abnormal, it does not mean that there is a problem. It means that more information is needed. Your health care provider can explain what the test results mean and possible next steps. You may need diagnostic testing.
  • Diagnostic tests show whether or not you or your baby have a certain problem.

It is your choice whether or not to get the prenatal tests. You and your health care provider can discuss the risks and benefits of the tests, and what kind of information the tests can give you. Then you can decide which ones are right for you.

Dept. of Health and Human Services Office on Women's Health


Prenatal Diagnosis
Pregnancy and Reproduction
Genetics/Birth Defects
Diagnostic Tests
Female Reproductive System
... Your health care provider can explain what the test results mean and possible next steps. You may need diagnostic testing. Diagnostic tests show whether or not you ...
Kidney Tests
National Library of Medicine
Kidney Biopsy
Kidney Function Tests
Kidney Function Panel
Kidney Panel
Renal Function Panel

You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. Your kidneys filter and clean your blood, taking out waste products and making urine. Kidney tests check to see how well your kidneys are working. They include blood, urine, and imaging tests.

Early kidney disease usually does not have signs or symptoms. Testing is the only way to know how your kidneys are doing. It is important for you to get checked for kidney disease if you have the key risk factors - diabetes, high blood pressure, heart disease, or a family history of kidney failure.

Specific kidney tests include

  • Glomerular filtration rate (GFR) - one of the most common blood tests to check for chronic kidney disease. It tells how well your kidneys are filtering.
  • Creatinine blood and urine tests - check the levels of creatinine, a waste product that your kidneys remove from your blood
  • Albumin urine test - checks for albumin, a protein that can pass into the urine if the kidneys are damaged
  • Imaging tests, such as an ultrasound - provide pictures of the kidneys. The pictures help the health care provider see the size and shape of the kidneys, and check for anything unusual.
  • Kidney biopsy - a procedure that involves taking a small piece of kidney tissue for examination with a microscope. It checks for the cause of kidney disease and how damaged your kidneys are.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Kidney Function Tests
Kidneys and Urinary System
Diagnostic Tests
You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. Your kidneys filter and clean your blood, taking out waste ...
Diagnostic Imaging
National Library of Medicine
Imaging

Diagnostic imaging lets doctors look inside your body for clues about a medical condition. A variety of machines and techniques can create pictures of the structures and activities inside your body. The type of imaging your doctor uses depends on your symptoms and the part of your body being examined. They include

  • X-rays
  • CT scans
  • Nuclear medicine scans
  • MRI scans
  • Ultrasound

Many imaging tests are painless and easy. Some require you to stay still for a long time inside a machine. This can be uncomfortable. Certain tests involve exposure to a small amount of radiation.

For some imaging tests, doctors insert a tiny camera attached to a long, thin tube into your body. This tool is called a scope. The doctor moves it through a body passageway or opening to see inside a particular organ, such as your heart, lungs, or colon. These procedures often require anesthesia.


Diagnostic Imaging
Diagnostic Tests
... a small amount of radiation. For some imaging tests, doctors insert a tiny ... as your heart, lungs, or colon. These procedures often require anesthesia.
Laboratory Tests
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Blood Tests

Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor analyzes the test samples to see if your results fall within the normal range. The tests use a range because what is normal differs from person to person. Many factors affect test results. These include

  • Your sex, age and race
  • What you eat and drink
  • Medicines you take
  • How well you followed pre-test instructions

Your doctor may also compare your results to results from previous tests. Laboratory tests are often part of a routine checkup to look for changes in your health. They also help doctors diagnose medical conditions, plan or evaluate treatments, and monitor diseases.


Clinical Laboratory Techniques
Diagnostic Tests
Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor analyzes the test samples to see if your results fall within ...
A1C
National Library of Medicine
Hemoglobin A1c
Glycohemoglobin
HbA1C
Hemoglobin A1C test

A1C is a blood test for type 2 diabetes and prediabetes. It measures your average blood glucose, or blood sugar, level over the past 3 months. Doctors may use the A1C alone or in combination with other diabetes tests to make a diagnosis. They also use the A1C to see how well you are managing your diabetes. This test is different from the blood sugar checks that people with diabetes do every day.

Your A1C test result is given in percentages. The higher the percentage, the higher your blood sugar levels have been:

  • A normal A1C level is below 5.7%
  • Prediabetes is between 5.7 to 6.4%. Having prediabetes is a risk factor for getting type 2 diabetes. People with prediabetes may need retests every year.
  • Type 2 diabetes is above 6.5%
  • If you have diabetes, you should have the A1C test at least twice a year. The A1C goal for many people with diabetes is below 7. It may be different for you. Ask what your goal should be. If your A1C result is too high, you may need to change your diabetes care plan.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Glycated Hemoglobin A
Diagnostic Tests
Diabetes Mellitus
... A1C alone or in combination with other diabetes tests to make a diagnosis. They also use the A1C to see how well you are managing your diabetes. This test is different from the blood sugar checks that ...
Thyroid Tests
National Library of Medicine
Thyroid panel

Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones control the rate of many activities in your body. They include how fast you burn calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. They are also used to diagnose and help find the cause of thyroid diseases such as hyperthyroidism and hypothyroidism. Thyroid tests include blood tests and imaging tests.

Blood tests for your thyroid include

  • TSH - measures thyroid-stimulating hormone. It is the most accurate measure of thyroid activity.
  • T3 and T4 - measure different thyroid hormones.
  • TSI - measures thyroid-stimulating immunoglobulin.
  • Antithyroid antibody test - measures antibodies (markers in the blood).

Imaging tests include CT scans, ultrasound, and nuclear medicine tests. One type of nuclear medicine test is the thyroid scan. It uses small amounts of radioactive material to create a picture of the thyroid, showing its size, shape, and position. It can help find the cause of hyperthyroidism and check for thyroid nodules (lumps in the thyroid). Another nuclear test is the radioactive iodine uptake test, or thyroid uptake test. It checks how well your thyroid is working and can help find the cause of hyperthyroidism.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Thyroid Function Tests
Endocrine System
Diagnostic Tests
Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones ...
Biopsy
National Library of Medicine

A biopsy is a procedure that removes cells or tissue from your body. A doctor called a pathologist looks at the cells or tissue under a microscope to check for damage or disease. The pathologist may also do other tests on it.

Biopsies can be done on all parts of the body. In most cases, a biopsy is the only test that can tell for sure if a suspicious area is cancer. But biopsies are performed for many other reasons too.

There are different types of biopsies. A needle biopsy removes tissue with a needle passed through your skin to the site of the problem. Other kinds of biopsies may require surgery.


Biopsy
Cancers
Diagnostic Tests
A biopsy is a procedure that removes cells or tissue from your body. A doctor called a pathologist looks at the cells or tissue under a microscope to check ...
Genetic Testing
National Library of Medicine
Paternity Testing
What is genetic testing?

Genetic testing is a type of medical test that looks for changes in your DNA. DNA is short for deoxyribonucleic acid. It contains the genetic instructions in all living things. Genetic tests analyze your cells or tissue to look for any changes in

  • Genes, which are parts of DNA that carry the information needed to make a protein
  • Chromosomes, which are thread-like structures in your cells. They contain DNA and proteins.
  • Proteins, which do most of the work in your cells. Testing can look for changes in the amount and activity level of proteins. If it finds changes, it might be due to changes in your DNA.
Why is genetic testing done?

Genetic testing may be done for many different reasons, including to

  • Find genetic diseases in unborn babies. This is one type of prenatal testing.
  • Screen newborn babies for certain treatable conditions
  • Lower the risk of genetic diseases in embryos that were created using assisted reproductive technology
  • Find out if you carry a gene for a certain disease that could be passed on to your children. This is called carrier testing.
  • See whether you are at increased risk of developing a specific disease. This may be done for a disease that runs in your family.
  • Diagnose certain diseases
  • Identify genetic changes that may be causing or contributing to a disease that you were already diagnosed with
  • Figure out how severe a disease is
  • Help guide your doctor in deciding the best medicine and dosage for you. This is called pharmacogenomic testing.
How is genetic testing done?

Genetic tests are often done on a blood or cheek swab sample. But they may also be done on samples of hair, saliva, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. The sample is sent to a laboratory. There, a lab technician will use one of several different techniques to look for genetic changes.

What are the benefits of genetic testing?

The benefits of genetic testing include

  • Helping doctors make recommendations for treatment or monitoring
  • Giving you more information for making decisions about your health and your family's health:
    • If you find out that you are at risk for a certain disease, you might take steps to lower that risk. For example, you may find out that you should be screened for a disease earlier and more often. Or you might decide to make healthy lifestyle changes.
    • If you find out that you are not at risk for a certain disease, then you can skip unnecessary checkups or screenings
    • A test could give you information that helps you make decisions about having children
  • Identifying genetic disorders early in life so treatment can be started as soon as possible
What are the drawbacks of genetic testing?

The physical risks of the different types of genetic testing are small. But there can be emotional, social, or financial drawbacks:

  • Depending on the results, you may feel angry, depressed, anxious, or guilty. This can be especially true if you are diagnosed with a disease that does not have effective treatments.
  • You may be worried about genetic discrimination in employment or insurance
  • Genetic testing may give you limited information about a genetic disease. For example, it cannot tell you whether you will have symptoms, how severe a disease might be, or whether a disease will get worse over time.
  • Some genetic tests are expensive, and health insurance might only cover part of the cost. Or they may not cover it at all.
How do I decide whether to be tested?

The decision about whether to have genetic testing is complex. In addition to discussing the test with your health care provider, you can meet with a genetic counselor. Genetic counselors have specialized degrees and experience in genetics and counseling. They can help you understand the tests and weigh the risks and benefits. If you do get a test, they can explain the results and make sure that you have the support that you need.


Genetic Testing
Pregnancy and Reproduction
Genetics/Birth Defects
Diagnostic Tests
What is genetic testing? Genetic testing is a type of medical test that looks for changes in your DNA. DNA is short for deoxyribonucleic acid. It contains ...